1. Field of the Invention
The present invention relates to a device and method for detecting the running direction of an automotive vehicle.
2. Description of the Prior Art
It is known that the distribution of the terrestrial magnetic field is disturbed when two automotive vehicles running in opposite directions pass by each other or when an automotive vehicle is running in a tunnel, beneath an overpass of a highway or a railway, or in a street surrounded by tall buildings.
Prior art methods for detecting the running direction of an automotive vehicle on the basis of the detection of the terrestrial magnetic field have suffered from the problem of having difficulty in correctly detecting the running direction the vehicle in regions where the distribution of the terrestrial magnetic field is disturbed.